Scraper latch



Oct. 26, 1943.

H. c. FRENCH 2,332,628

S CRAPER LAT CH Filed Nov. 17, 1941 2 Sheets-Sheet 1 INVENTOR.

x-fi s fi m H. C. FRENCH SCRAPER LATCH Oct. 26, 1943.

Filed NOV. 17, 1941 2 Sheets-Sheet 2 AT TORNEY's.

Patented Oct. 26, 1943 scaarna m'rcn Henry 0. French, Elm Grove, Wia,assignor to The Hell 00., Milwaukee, Wis., a corporation of WisconsinApplication November 17, 1941, Serial No. 419,377

2 Claims. (Cl. 37-126) provide a scraper latch, effective relative tobowl raising mechanism, which is automatically operated when the scraperbowl moves to and from certain positions.

A further general object of the invention is to provide latch mechanismfor insuring retention of a scraper bowl in a desired elevated positionand which takes the load oil of the scraper bowl operating mechanism orinstrumentalities.

Certain forms of scrapers, particularly of the so-called dig and carrytype, have articulated front and rear wheeled frames carrying bowl andgate members. Due to the articulation as between the wheeled frames, andthe mounting of the bowl and gate members, when the bowl is in elevatedor load carrying position the main operating mechanism must be employedand kept under power for the purpose of retaining the bowl in saidelevated position, thereby imposing undesirable strain on suchmechanism.

With the above in mind, a more specific object of the present inventionis to provide a latch mechanism as between certain relatively movableelements of a scraper which are brought into juxtaposition when the bowlis elevated, such latch mechanism being effective to hold the bowl inelevated position and taking the strain and load oil of the meansemployed for raising the bowl.

The undesirable strain and load on a scraper bowl operating mechanism isalso pronounced in an articulated frame scraper wherein a beam, hingedlyassociated with the frame structure, is releasably retained in a loweredor down-swung position when the scraper bowl iselevated, it being usualto provide with an arrangement of this type, cables for operating thebowl mechanism extended over the free end of the beam,

together with cables between a fixed frame part and the outer end of thebeam. With this form of structure, the cable between the fixed frameportion and the outer end of the beam is ordinarily reeled in and heldtaut by a winch when the beam is in a down-swung position with the bowlraised, whereby the taut cable holding the beam in the down-swungposition is under severe strain and tension and is solely responsible.for

holding the scraper bowl in elevated load confining position. Thepresent practice is. to operate scrapers at relatively high speeds,particularly when'carrying material in the closed and elevated bowl, anda scraper constructed as last described, while travelling at arelatively high rate of speed would be severely damaged if the tautbeamcable should snap or break, thereby releasing the down-swung beam andpermitting the bowl assembly to drop and contact the ground.

It is a further specific object of the present invention to overcome thelast mentioned objections and difliculties by providing a cableoperated, beam equipped scraper with automatically operating latchmechanism as between a fixed scraper frame part and the movable beam,whereby the latch constitutes the sole means for releasably holding thebeam in a desired effective position, relieving strain and load on thebeam controlling cable and permitting the scraper operating cables to beslack while the scraper is travelling and transporting material.

A further specific object of the invention is to provide a scraper latchwhich automatically latchingly engages a complementary element duringthe normal operating movement of the scraper beam to bowl raisingposition, and which is automatically manipulated to releasing positionby an additional movement of the beam followed by the normal operatingmovement of the beam to bowl lowering position.

A further object of the invention is to provide a scraper latch withwhich a; scraper may be readily equipped with a minimum of parts andmodifications.

A further object of the invention is to provide a scraper latch which isof very simple construction, is efficient and automatic in operation, isstrong and durable, is inexpensive, and is well adapted for the purposesdescribed.

With the above and other objects in view, the invention consists of theimproved scraper latch and its parts and combinations as set forth inthe claims, and all equivalents thereof.

In the accompanying drawings in which the same reference charactersindicate the same parts in all of the views:

Fig. l is a side view, slightly in perspective, of a cable operatedscraper equipped with the improved latch mechanism, attached to atractor which furnishes the motive power for the scraper;

Fig. 2 is an enlarged central longitudinal vertical sectional viewthrough a scraper equipped with the improved latching mechanism showingthe parts in load confining and transporting beam element from thelatch; and

Fig. 5 is an enlarged fragmentary detail view, with parts broken awayand in section, showing the latch in operative position with a dottedline showing of the latch in a releasing position.

While the invention is herein disclosed in connection with a specificform of beam equipped, cable operated scraper, it should be understoodthat this is merely by way of illustration, and the invention is nottobe limited thereto. ,4

Referring now more particularly to thefl rawings, the improved scrapershown therein" y way of illustration, comprises in general a sturdyfront frame 8 transportable by and swingably supported upon a frontwheel supported carriage 9. This front frame also has laterallyseparated rearwardly and downwardly extending integral side arms I0.There is also a sturdy rear frame transportable by and swingably mountedupon a rear wheel supported carriage |2 having laterally separated,forwardly extending, integral opposite 'side walls l3 disposed betweenthe rear ends of the front frame arms l and rigidly interconnected bymeans of a curved rear wall |4 having upper and lower cross beams l5 andI6 respectively associated therewith, together with front cross beams I!and I8 located forwardly of the wall |4 to provide an open bottom.Alined pivot pins |9 articulably interconnect the rear ends of the frontframe arms II) with the medial outer portions of the rear frame sidewalls l3 whereby a jack-knife action of the frame is attainable,permitting raising and lowering of the load carrying bowl structure aswill hereinafter appear.

The load carrying bowl structure includes a fiat load supporting bottomplate 20 pivotally suspended at its forward end, by means of a pivotshaft 22, from the front lower cross beam I1 in close proximity to atransverse scraper or cut-- ting blade 2| which is carried by said beamH. The bottom plate 20 has its rear end engageable with lugs 23 securedto the lower rear beam l6 and is swingable upwardly along the curvedrear wall I4 and said plate 20 also has a bracket 24 rigidly attached toits medial portion.

The front end of the bucket is controlled by a load confining apron orfront gate'25 having integral opposite curved side arms 26 disposedbetween and swingably suspended from the side walls l3 of the rear frameII by means of alined pivot pins 21. Said front gate 25 has its lowercut off edge 28 cooperable with and swingable beneath the cutting edgeof the blade 2| to confine material 29 within the space bounded by thewalls l3 and I4 above the bottom plate 20, which is in effect thescraper bucket.

At the forward end of the mechanism there is a bowl lift beam 30 whichis swingably suspended from the front frame 8 by means of a pivot shaft3|. When the scraper frame elements articulate for raising and loweringmovements ofthe bowl. I

the bowl lift beam 30 moves to and from a downswung position such as isshown in Figs. 1 and .2 of the drawings, The beam 30 has its rear endconnected to the medial portion of .the upper front cross beam l8 by aset of links 32 and pivot 5 pins.

The mechanism for effecting swinging of the front gate 25 and of thebottom plate 29 comprises a single cable 31 which first raises the frontgate 25 and subsequently tilts the bottom plate 20 to discharge theload. Details of the sheaves, cables and other mechanism in connectionwith the gate 25 and bottom plate 20 will not be described in detail asthey are similar to that shown and described in my Patent No.

Re. 21,885. Suffice it to say that a pull on the cable 31 will firstelevate the front gate 25 and will thereafter swing the bottom plateupwardly, while release of the pull on the cable 31 will permit gravityto first lower the bottom plate 20 20 and thereafter lower the frontgate 25.

Mounted upon the forward swinging end of the bowl lift beam 30 is a setof alined sheaves 38 which are joumalled on a shaft 39. The forwardupper portion of the front frame 6 carries a shaft 40 upon which ismounted another set of sheaves 4|. The cable 31 for actuating the gate25 and bottom plate 20 passes under a floating sheave 42, coacts withone of the sheaves 38 and one of the sheaves 4|, and then extendsforwardly between certain guide rollers 43 to a hoisting winch 44located on the rear of a propelling tractor 45.

The mechanism-for permitting articulation between the front and rearframes 8 and II about the pivot shafts I9, thereby effecting raising andlowering movements of the bowl assembly, comprises a second cable 46which extends rearwardly from the tractor winch 44, and after passingbetween certain of the guide rollers 43 this cable 46 passessuccessively about the sheaves 4| and 38 and finally has an end securedto a cable connector 41 mounted on the beam 30. With the arrangementdescribed, when a pull is exerted on the cable 46, the beam 30 will beswung about its pivot shaft 3| from the position shown in Fig. 3 to adown-swung position similar to that'shown in Figs. 1, 2 and 5, therebyswinging the frames 8 and II relative to each other about the pivotshafts l9 and elevating the cutting blade 2|,

50 which in effect constitutes a raised position of the bucketstructure. When the pull on the cable 46 is released. gravity actingupon the rear frame II and associated parts, together with the weight ofthe material 29, will cause the scraper blade 2| to lower more or lesstoward the ground. This action will also tend'to swing the front end ofthe bowl lift beam 30 from the position of Figs. 1 and 2 to an upwardlydirected position. Such movement of the beam and consequent moveunlessthe bowl lift beam 30 is released and is permitted to freely move to theupwardly directed position. The cable 31, which actuates the front gate25, engages certain of the sheaves 36 and 4|, one ofwhich'is carried bythe swinging beam 30. Hence,the gate 25 will also be affected by raisingand lowering the cutting blade 2| independently of its operation by thecable 31. Thissecondary movement of the gate 25 is such that thematerial 29 will be most effectively retained within the =bucketstructure as the blade 2| is raised and lowered.

thus fargiven it is evident that when the cable 46 is reeled in by thetractor borne winch 44,

ment of the bowl structure is not permissible From the description ofthe scraper mechanism such reeling in of the cable will exert a downwardpull on the outer end of the beam 30, causing the beam to move from anupwardly directed position to the down-swung position of Fig. 2.

This operation of reeling in the cable 46 and lowering the beam 30materially reduces the distance between the sheaves 38 and 4| so thatthe cable extents connecting the sheaves 38 and 4| are materiallyshortened. In prior structures it was necessary, in order to retain thebeam 3|! in said lowered position, to keep the winch or other powerinstrumentality under operation or to set the winch brake so that thecable 46 is maintained in its shortened relationship and is taut asbetween the winchand sheaves 4i and as between the sheaves 4| and 38.This position of the beam 30 is the beam position when the bowlmechanism is elevated, as previously described, for load transportingpurposes. Present day practice is to run scrapers at a relatively highrate of speed in transporting a load. With the prior arrangementdescribed it must be obvious that the operating mechanism and the "cable46 was under a severe strain and load during the periods when thescraper was being hauled to I transport a load, with the bucket raised.If the winch brake should accidentally release or if the cable 46 shouldbreak or snap, the beam 30 would automatically be freed and the meansfor retaining the bucket and load in a raised position would beineffective, whereupon the bucket and load would drop to or toward theground with the result that considerable damage might be done to thescraper or associated mechanisms.

An important aspect of the present invention is the provision of simple,efiicient and automatic means for positively retaining the bucketmechanism in a position insuring elevation of the bucket, without strainon the cables, winch, or other operating means. Although the inventionis susceptible of being carried out in other forms and arrangements, itis found convenient, in connection with a bowl lift beam equipped, cableoperated scraper to carry out the specific improvementsin the followingmanner:

fixed transverse pivot shaft 52. A lower portion or the latch hook 5|has pivotally secured thereto a clevis 63 to which is aflixed one end ofa rod 54, the other end of said rod being slidable relative to a spacedguide plate 65 rigidly secured on the top of the members It. About themajor portion of the rod 54 there is a compressed and confined coiledspring 56. The spring and rod arrangement is such that when the latchhook 5| is moved in either direction from dead center the spring exertsa force to quickly snap it to an extreme position on either side of deadcenter.

Normally the latch hook 5| assumes a position as shown in Figs. 3 and 5,with the latch hook in a relatively upright position having at the topend thereof a relatively wide opening or mouth 51. An intermediate underportion of the beam 30 has a hollow or open section between the lowerside wall portions of which is extended a rigid, transverse, relativelymassive latch pin 58.

When the bowl assembly of the scraper is in lowered position-that is,when the bottom plate 20 is projecting downwardly for digging purposesand the front gate 25 is raised, the bowl lift beam 30, as waspreviously explained, assumes an upwardly directed position as depictedin Fig. 3. If it is desired to raise the bowl structure for loadconfining and transporting purposes, the winch 44 is of course operatedto reel in the cable 31 and to likewise reel in the cable 46. Thisaction causes the beam 30 to swing on its pivot II in a counterclockwisedirection relative to the drawings and the beam carried transverse latchpin 58 will ultimately contact the outer surface or the curved noseextremity 59 or the latch hook 5|, slightly rocking the latch hook in acounterclockwise direction and permitting the latch pin to move over theextremity of the hook nose 59 and into the mouth 51 until it engages aninner surface portion 60 of the latch hook substantially below the innercurved retaining surface SI of the latch hook nose. By this time thebowl structure will have been raised to its load carrying position andthereupon the winch is operated to provide slack in the cables with theresult that the beam 30 will then snap upwardly slightly, firmlyengaging th latch pin 58 in the curved recess M of the nose end of thelatch hook, as shown in full lines in Fig. 5 and in broken lines in Fig.3. This constitutes the latched Position of the beam 30 and with thebeam thus engaged by the latch hook 5! it is unnecessary to have thecables taut or under tension and it is further unnecessary to have thewinch or winch brake in operation, thus easing strain and tension onthese various parts. The securement of the beam in lowered position bythe latch hook insures retention of the scraper bucket in its elevatedposition and the scraper may be transported at a rapid rate or speedwithout any danger of having the load accidentally dropped.

When it is desired to release the engaged beam 30 and thereby lower thebucket structure, the winch is first operated to draw in on the cable 46to pull the outer end of the beam 30 down slightly, causing the latchpin 58 to ride downwardly on the inner surface of the latch hook andaway from the hooking end thereof. A relatively small movement of thebeam in the direction indicated will cause, through the downwardpressure exerted by the latch pin 58 against a side arm of the hook 5|,a pivotal movement of the hook in a counterclockwise direction relativeto the drawings so as to swing the hook beyond dead center, whereuponthe spring 56 will snap it to a position at an angle relative to itsoriginal position, as shown in Fig. 4, and in dotted lines in Fig. 5.After the latch hook snaps to the latter position the cables areslackened and as before mentioned, gravity and the weight of thestructure and load will cause the frame members to swing on the pivot l9and the beam 30 will commence moving in a clockwise direction (relativeto the drawings) toward its raised or upwardly directed position. Duringthe latter movement, the latch pin 58 rides upwardly alon the inner camsurface 62 of the latch hook, ultimately striking the eccentricallycurved extremity thereof and thus rocking the latch hook 5! in aclockwise direction (relative to the drawings) with the result that uponsufficient movement of the beam 30 the latch hook will be rocked overits dead center position and the spring 56 will then snap it into itsupright position, as in Fig. 3, whereupon continued upward movement ofthe beam 30 will cause th latch pin 58 to move entirely free of thelatch hook 5|, thereby effectively automatically releasing the beam andpermitting lowering and opening or the bucket structure.

From the above described construction and mode of operation of theimproved scraper latch it will be evident that the latch automaticallyoperates to effect securement and release of the bow. lift beam duringnormal operating movements of said beam in both directions. Theengagement efiected by the latch is positive and there is no dependencyon cables or other mechanism for holding the parts, including thescraper bucket, in retained position, thereby insuring safe operationand travel of a loaded scraper.

Although the improved scraper latch has been described in connectionwith a cable operated scraper it is obvious that the latch mechanismcould be incorporated between relatively movable members in a scraper orlike machine which is hydraulically or otherwise controlled andoperated.

The improved scraper latch mechanism is incorporated in a scraper withlittle modification and with a minimum of parts. It is extremely simplein construction and operation, and is well adapted for the purposes setforth.

What is claimed as the invention is:

1. In a scraper having relatively movable ele-- ments operativelyassociated with a movable bucket assembly, a pair of complementary latchelements carried respectively by adjacent portions of a pair of saidelements and automatically engageable and disengageable solely uponmovements of the bucket assembly and relative movements of saidelements, one of said latch elements comprising a hook having anentrance mouth with projections and cam surfaces thereadjacent, meansrockingly mounting the end of the hook opposite the mouth on one of saidad- Jacent movable elements, and spring means to snap the hook to arocked position on either side of dead center, the other of said latchelements consisting of a pin rigidly carried by the other of saidadjacent movable elements and movable into the hook through the entrancemouth thereof and engageable with said cam surfaces to rock the hook indifferent directions.

2. In a scraper having hingedly connected front and rear wheeled frames,the rear frame including a bowl structure, an operating cable having anend extending to and operable from a pulling vehicle, means associatedwith said cable and responsive to a pull thereon, for raising said bowlstructure to transporting position, latching mechanism including apivotal latch element for locking said means in a position to hold thebowl in said transporting position after the cable has been pulled,means included in said latching mechanism and operable in response to afurther pull on the same cable for causing pivotal movement of saidpivotal latch element to releasing position, and means included in saidlatching mechanism operable in response to a lowering movement of thebowl structure after its release for causing pivotal movement of saidpivotal latch element back to its set position.

HENRY C. FRENCH.

